Oligomycin A is an antibiotic that works by blocking a proton (H ) channel in ATP synthase, inhibiting the action of the enzyme. The primary effect of this antibiotic is: Group of answer choices decreased ATP synthesis due to a decreased hydrogen ion gradient across the inner mitochondrial membrane. increased ATP synthesis due to an increased hydrogen ion gradient across the inner mitochondrial membrane. decreased ATP synthesis due to the inhibition of oxidative phosphorylation of ADP. increased ATP synthesis due to the promotion of oxidative phosphorylation of ADP.